dear Madhusudan,

B.TECH IN CSE-

B.Tech in cse is a professional couse. It offers the most specialization and is better per se as compared to both the above courses. B.Tech has comparatively the most number of students applying per year. B.Tech, on the other hand it requires clearing an entrance exam almost for addmission in any college in our country. There are state entrances and  also national level entrances which conduct their exams, rank students according to their marks .It is a four year course devided in eight semesters.  B.Tech has better placements (of course, it depends on the college as well). The IT industry is booming and much of the credit to that is due to the engineers. Candidates passing out from the top notch colleges get jobs with attractive salaries in almost all the biggest companies.Good quality computer engineers both in India and abroad are recruited in great numbers by multi-national companies. Computer Engineers who have completed their B Tech program are not only in great demand in IT industries as well as in airlines, banks and manufacturing industry.

BCA-

Bachelor in Computer Application (BCA) is not a professional  course. It is a degree course for the students who want to make their career in the IT (Information Technology) field. The duration of the course is 3 years and divided into 6 semesters. It comprises of the subjects like database, networking, data structure, core programming languages like ‘C’ and ‘java’. This course provides a lot of opportunities to the students who are interested in computer field and wants to work in the IT sector as programmer or software developer. This course is designed specifically for students who are interested in learning computer languages.Colleges may or may not conduct entrance exams for admissions. Although, all the top colleges intake students based on the entrance exam.Students pursuing BCA can start their career with both, government as well as private sector. The top colleges offer good placement opportunities.

hope this helps.